Fuel injection system and method of operating the same for an engine

Abstract

A fuel injector is coupled to an engine. The fuel injector includes an injection opening configured to vary in cross-section between a open state and a fully closed state. The fuel injector is configured to provide a plurality of discrete commanded fuel injections into an engine cylinder by modulating the size of the injection opening without completely closing the opening to the fully closed state.

1. A vehicle, comprising:
 an engine comprising a piston disposed in a cylinder and a fuel injector coupled to the engine, wherein the fuel injector comprises an injection opening configured to vary in cross-section between open and closed states, and the fuel injector is configured to modulate the cross-section of the injection opening to generate a plurality of discrete fuel injections without completely closing the injection opening from one injection to another of the plurality of discrete fuel injections. 
 
     
     
       2. The vehicle of  claim 1 , wherein the engine comprises a diesel engine, the vehicle comprises a locomotive, and a turbocharger is coupled to the engine. 
     
     
       3. The vehicle of  claim 1 , wherein the fuel injector is configured to modulate the cross-section of the injection opening to generate at least two or more equal quantity fuel injections without completely closing the injection opening between the equal quantity fuel injections. 
     
     
       4. The vehicle of  claim 1 , wherein the fuel injector is configured to modulate the cross-section of the injection opening to generate at least two or more unequal fuel injections without completely closing the injection opening between the unequal fuel injections, wherein the unequal fuel injections include a main fuel injection after two or more pilot fuel injections, and the main fuel injection comprises a fuel quantity substantially larger than each of the two or more pilot fuel injections. 
     
     
       5. A fuel injector configured to provide a plurality of fuel injections into an engine cylinder, the fuel injector comprising:
 a fuel injection housing; 
 a fuel injection valve disposed in the fuel injection housing; and 
 a controller coupled to the fuel injection valve, wherein the controller is configured to modulate the fuel injection valve between open and closed positions to generate a plurality of discrete fuel injections without completely closing the fuel injection valve from one injection to another of the plurality of discrete fuel injections. 
 
     
     
       6. The fuel injector of  claim 5 , wherein the controller is configured to modulate the fuel injection valve to generate at least two or more equal quantity fuel injections without completely closing the fuel injection valve between the equal quantity fuel injections. 
     
     
       7. The fuel injector of  claim 6 , wherein the controller is configured to modulate the fuel injection valve to generate at least two or more unequal fuel injections without completely closing the fuel injection valve between the unequal fuel injections, wherein the unequal fuel injections include a main fuel injection after two or more pilot fuel injections, and the main fuel injection comprises a fuel quantity substantially larger than each of the two or more pilot fuel injections. 
     
     
       8. The fuel injector of  claim 5 , comprising a pressure sensor and a position sensor coupled to the controller and configured to detect feedback including a fuel pressure and a fuel injection valve position, respectively, wherein the controller modulates the fuel injection valve without completely closing the fuel injection valve from one injection to another based at least partially on the feedback. 
     
     
       9. A system, comprising:
 a controller configured to control a fuel injector to provide a plurality of fuel injections into an engine cylinder, wherein the controller is configured to modulate a fuel injection valve of the fuel injector between open and closed positions without completely closing the fuel injection valve from one injection to another of the plurality of fuel injections. 
 
     
     
       10. The system of  claim 9 , wherein the controller is configured to modulate the fuel injection valve to generate at least two or more equal quantity fuel injections without completely closing the fuel injection valve between the equal quantity fuel injections. 
     
     
       11. The system of  claim 10 , wherein the controller is configured to modulate the fuel injection valve to generate at least two or more unequal fuel injections without completely closing the fuel injection valve between the unequal fuel injections. 
     
     
       12. The system of  claim 9 , comprising a pressure sensor and a position sensor coupled to the controller and configured to detect feedback including a fuel pressure and a fuel injection valve position, respectively, wherein the controller modulates the fuel injection valve without completely closing the fuel injection valve from one injection to another based at least partially on the feedback. 
     
     
       13. The system of  claim 9 , comprising a compression ignition engine having the controller. 
     
     
       14. The system of  claim 13 , comprising a vehicle having the compression ignition engine and the controller. 
     
     
       15. A non-transitory tangible medium comprising a computer program, comprising:
 programming instructions disposed on the non-transitory tangible medium, wherein the programming instructions include instructions to provide a plurality of fuel injections into an engine cylinder via a modulation of a valve of a fuel injector, wherein the modulation comprises movement of the valve between open and closed positions without completely closing the valve from one injection to another of the plurality of fuel injections. 
 
     
     
       16. A method, comprising:
 providing a modulated fuel injection to an engine cylinder by modulating a valve of a fuel injector, wherein modulating the valve comprises moving the valve between open and closed positions without completely closing the valve to generate a plurality of discrete fuel injections. 
 
     
     
       17. The method of  claim 16 , wherein modulating the valve comprises moving the valve to generate two or more unequal fuel injections without completely closing the valve between the unequal fuel injections. 
     
     
       18. The method of  claim 16 , wherein modulating the valve comprises moving the valve to generate two or more generally equal quantity fuel injections without completely closing the valve between the generally equal quantity fuel injections. 
     
     
       19. The method of  claim 16 , wherein modulating the valve comprises moving the valve to generate a main fuel injection after two or more pilot fuel injections without completely closing the valve between the main fuel injection and the pilot fuel injections, and the main fuel injection comprises a fuel quantity substantially larger than each of the two or more pilot fuel injections. 
     
     
       20. The method of  claim 16 , wherein modulating the valve of the fuel injector without completely closing the valve comprises reducing wear of the valve, the fuel injector, or a combination thereof. 
     
     
       21. The method of  claim 16  wherein modulating the valve comprises actuating the valve at a first time to open the valve to inject a first fuel quantity, waiting for the valve to move from an open position toward a closed position without allowing the valve to reach the closed position, and actuating the valve at a second time to open the valve to inject a second fuel quantity before the valve reaches the closed position. 
     
     
       22. The method of  claim 16 , wherein modulating the valve comprises varying an opening to pass fuel for each of the plurality of discrete fuel injections without completely closing the opening between the plurality of discrete fuel injections. 
     
     
       23. The method of  claim 16 , comprising actuating the valve between a fully closed, an open position and a partially closed position during each fuel injection into the engine cylinder based on a fuel pressure, a position of the valve, or a combination thereof. 
     
     
       24. The method of  claim 16 , comprising reducing an initial fuel injection rate into the engine cylinder by actuating the valve between a normally closed, an open position and a partially closed position during each fuel injection into the engine cylinder. 
     
     
       25. The method of  claim 16 , comprising adjusting fuel injection rate by actuating the valve between a fully closed, an open position and a partially closed position during each fuel injection into the engine cylinder.